The function of this core is to perform the qualitative and quantitative analyses of all the engineered antibody constructs and their conjugates. This will be done by solid phase enzyme immunoassay (EIA). The routine procedures for preclinical analysis of immunoreactivity (EIA, bead assay), stability (FPLC), and in vivo animal biodistribution and pharmacokinetic characteristics will be carried out in this core. These studies will provide the preclinical information necessary for assessing the suitability of the radioimmunoconjugates for human study. The patient tissue analyses will include blood, urine and fecal clearance as well as tissue uptake of the radiolabeled monoclonal antibody conjugates. Surgically resected patient tissues (normal and neoplastic), and bone marrow biopsies will be analyzed for uptake of the radiolabeled antibodies (%ID/g) and the molecular species present (FPLC). Blood, urine and feces will also be analyzed for the molecular species present. Tissue content of tumor associated antigen CEA will also be measured to determine the correlation between antigen expression and antibody uptake. Anti-antibody measurements will be undertaken to determine the patient immune response to different antibody preparations.